Factory

abstract class Factory<Key : Any, Value : Any>

kotlin.Any
↳	androidx.paging.DataSource.Factory

Factory for DataSources.

Data-loading systems of an application or library can implement this interface to allow LiveData<PagedList>s to be created. For example, Room can provide a DataSource.Factory for a given SQL query:

@Dao
interface UserDao {
    @Query("SELECT * FROM user ORDER BY lastName ASC")
    public abstract DataSource.Factory<Integer, User> usersByLastName();
}

In the above sample, Integer is used because it is the Key type of PositionalDataSource. Currently, Room uses the LIMIT/OFFSET SQL keywords to page a large query with a PositionalDataSource.

Summary

Public constructors
<init>() Factory for DataSources.

Public methods
() -> PagingSource<Key, Value>	asPagingSourceFactory(fetchDispatcher: CoroutineDispatcher = Dispatchers.IO)
abstract DataSource<Key, Value>	create() Create a DataSource.
open DataSource.Factory<Key, ToValue>	map(function: Function<Value, ToValue>) Applies the given function to each value emitted by DataSources produced by this Factory.
open DataSource.Factory<Key, ToValue>	map(function: (Value) -> ToValue) Applies the given function to each value emitted by DataSources produced by this Factory.
open DataSource.Factory<Key, ToValue>	mapByPage(function: Function<List<Value>, List<ToValue>>) Applies the given function to each value emitted by DataSources produced by this Factory.
open DataSource.Factory<Key, ToValue>	mapByPage(function: (List<Value>) -> List<ToValue>) Applies the given function to each value emitted by DataSources produced by this Factory.

Extension functions

From androidx.paging Flowable<PagedList<Value>> DataSource.Factory<Key, Value>.toFlowable(config: PagedList.Config, initialLoadKey: Key? = null, boundaryCallback: PagedList.BoundaryCallback<Value>? = null, fetchScheduler: Scheduler? = null, notifyScheduler: Scheduler? = null, backpressureStrategy: BackpressureStrategy = BackpressureStrategy.LATEST) Constructs a Flowable<PagedList>, from this DataSource.Factory, convenience for RxPagedListBuilder. Flowable<PagedList<Value>> DataSource.Factory<Key, Value>.toFlowable(pageSize: Int, initialLoadKey: Key? = null, boundaryCallback: PagedList.BoundaryCallback<Value>? = null, fetchScheduler: Scheduler? = null, notifyScheduler: Scheduler? = null, backpressureStrategy: BackpressureStrategy = BackpressureStrategy.LATEST) Constructs a Flowable<PagedList>, from this DataSource.Factory, convenience for RxPagedListBuilder. LiveData<PagedList<Value>> DataSource.Factory<Key, Value>.toLiveData(config: PagedList.Config, initialLoadKey: Key? = null, boundaryCallback: PagedList.BoundaryCallback<Value>? = null, fetchExecutor: Executor = ArchTaskExecutor.getIOThreadExecutor()) Constructs a LiveData<PagedList>, from this DataSource.Factory, convenience for LivePagedListBuilder. LiveData<PagedList<Value>> DataSource.Factory<Key